Asthma and Its Many Unmet Needs: Directions for Novel Therapeutic Approaches

Transcription

1 Asthma and Its Many Unmet Needs: Directions for Novel Therapeutic Approaches William W. Busse,, M.D. University of Wisconsin School of Medicine and Public Health Madison, WI, USA Disclosure Slide Employment University of Wisconsin Financial Interests Advisory Boards: GSK, Merck, Wyeth, Pfizer, Centocor, Amgen, Johnson & Johnson Consultant: Novartis, Genetech, Boehringer Ingelheim Research Interests NHLBI, NIAID, Novartis, Ception, MedImmune, GSK, AstraZeneca Organizational Interests AAAAI, ATS, AAP, ACAAI, AAI Gifts Nothing to Disclose Other Interests Nothing to Disclose

2 Objectives: Review current approaches to asthma treatment Review the effectiveness of guideline approaches to asthma Introduce the concept of asthma phenotypes Discuss approaches to personalized asthma treatment and development of novel therapeutic to meet these needs What characterizes asthma? Asthma is characterized by episodes of wheezing, cough, chest tightness and dyspnea The great majority of asthma patients have: Allergies (e.g. HDM, cat, molds, cockroach) Exercise-induced asthma (cold air) Nocturnal asthma Airway obstruction in asthma is typically reversible Nonspecific airway hyperresponsiveness can be demonstrated in the vast majority of patients with asthma

3 How have guidelines for asthma treatment benefitted care of this disease? Components of Severity Symptoms Classification of Asthma Severity (Youths 12 years of age and adults) Intermittent 2 days/week Mild >2 days/week but not daily Persistent Moderate Daily Severe Throughout the day Nighttime Awakenings 2x/month 3 4x/month >1x/week but not nightly Often 7x/week Impairment Normal FEV 1 /FVC: 8 19 yr 85% yr 80% yr 75% yr 70% Short-acting beta 2 -agonist use for symptom control (not prevention of EIB) Interference with normal activity Lung Function 2 days/week None Normal FEV 1 between exacerbations FEV 1 >80% predicted >2 days/week but not >1x/day Minor limitation FEV 1 >80% predicted Daily Some limitation FEV 1 >60% but <80% predicted Several times per day Extremely limited FEV 1 <60% predicted FEV 1 /FVC normal FEV 1 /FVC normal FEV 1 /FVC reduced 5% FEV 1 /FVC reduced >5% 0 2/year >2/year Risk Exacerbations (consider frequency and severity) Frequency and severity may fluctuate over time for patients in any severity category Relative annual risk of exacerbations may be related to FEV 1

4 Components of Severity Symptoms Classification of Asthma Severity (Youths 12 years of age and adults) Intermittent 2 days/week Mild >2 days/week but not daily Persistent Moderate Daily Severe Throughout the day Nighttime Awakenings 2x/month 3 4x/month >1x/week but not nightly Often 7x/week Impairment Normal FEV 1 /FVC: 8 19 yr 85% yr 80% yr 75% yr 70% Short-acting beta 2 -agonist use for symptom control (not prevention of EIB) Interference with normal activity Lung Function 2 days/week None Normal FEV 1 between exacerbations FEV 1 >80% predicted >2 days/week but not >1x/day Minor limitation FEV 1 >80% predicted Daily Some limitation FEV 1 >60% but <80% predicted Several times per day Extremely limited FEV 1 <60% predicted FEV 1 /FVC normal FEV 1 /FVC normal FEV 1 /FVC reduced 5% FEV 1 /FVC reduced >5% 0 2/year >2/year Risk Exacerbations (consider frequency and severity) Frequency and severity may fluctuate over time for patients in any severity category Relative annual risk of exacerbations may be related to FEV 1 Components of Severity Symptoms Classification of Asthma Severity (Youths 12 years of age and adults) Intermittent 2 days/week Mild >2 days/week but not daily Persistent Moderate Daily Severe Throughout the day Nighttime Awakenings 2x/month 3 4x/month >1x/week but not nightly Often 7x/week Impairment Normal FEV 1 /FVC: 8 19 yr 85% yr 80% yr 75% yr 70% Short-acting beta 2 -agonist use for symptom control (not prevention of EIB) Interference with normal activity Lung Function 2 days/week None Normal FEV 1 between exacerbations FEV 1 >80% predicted >2 days/week but not >1x/day Minor limitation FEV 1 >80% predicted Daily Some limitation FEV 1 >60% but <80% predicted Several times per day Extremely limited FEV 1 <60% predicted FEV 1 /FVC normal FEV 1 /FVC normal FEV 1 /FVC reduced 5% FEV 1 /FVC reduced >5% 0 2/year >2/year Risk Exacerbations (consider frequency and severity) Frequency and severity may fluctuate over time for patients in any severity category Relative annual risk of exacerbations may be related to FEV 1

5 How are these concepts incorporated into the Guidelines? Components of Severity Impairment Normal FEV 1 /FVC: 8 19 yr 85% yr 80% yr 75% yr 70% Risk Symptoms Nighttime awakenings Short-acting beta 2 -agonist use for symptom control (not prevention of EIB) Interference with normal activity Lung function Exacerbations (consider frequency and severity) Intermittent 2 days/week 2x/month 2 days/week None Normal FEV 1 between exacerbations FEV 1 >80% predicted FEV 1 /FVC normal 0 2/year Classification of Asthma Severity 12 years of age >2 days/week but not >1x/day Minor limitation FEV 1 >80% predicted >2/year Mild >2 days/week but not daily 3 4x/month FEV 1 /FVC normal Persistent Moderate Daily >1x/week but not nightly Daily Some limitation FEV 1 >60% but <80% predicted FEV 1 /FVC reduced 5% Frequency and severity may fluctuate over time for patients in any severity category Severe Throughout the day Often 7x/week Several times per day Extremely limited FEV 1 <60% predicted FEV 1 /FVC reduced >5% Relative annual risk of exacerbations may be related to FEV 1 Recommended Step for Initiating Treatment (See figure 4 5 for treatment steps) Step 1 Step 2 Step 3 Step 4 or 5 and consider short course of systemic oral corticosteroids In 2 6 weeks, evaluate level of asthma control that is achieved and adjust therapy accordingly.

6 Does this approach work? The Can Guideline-Defined Asthma Control Be Achieved? Gaining Optimal Asthma ControL (GOAL) Study E.D. Bateman et al. Am J Respir Crit Care Med 2004; 170:

7 GOAL Design Phase I Phase I 8- week control assessment Seretide 50/500 or FP 500 Seretide 50/250 or FP 250 Step 3 Seretide 50/100 or FP 100 Step 2 Step 1 Visit Week GOAL Study Patients (%) WELL CONTROLLED Asthma During Phase I 65% 71%* 52% 69%** FP Phase I Seretide Phase I 33% 51%** 20 0 Steroid-naive (S1) Low-dose ICS (S2) Moderate-dose ICS (S3) * P = **P < GOAL Study, Bateman E, et al ARJCCM 2004; 170:836

8 Given that asthma control is not universally achieved, what can be the next steps? Arthritis, anemia and asthma How are they all alike? They all are nonspecific and general characteristics of disease, describing swelling, low RBC numbers or reversible airway obstruction They shed almost no light on what caused these characteristics to develop Sally Wenzel, ATS 2010

9 Arthritis In rheumatology, no one would ever ultimately diagnose a patient with arthritis as the natural history, genetics, inflammatory processes and response to therapy will differ by which arthritis the patient has i.e., the understanding and treatment of RA will be vastly different from treatment of OA The same is likely true in asthma Sally Wenzel, ATS 2010 What is a phenotype? The relatively stable and observable characteristics of an organism resulting from interaction between its genetic make-up and environmental influences Peter Sterk, ATS 2010

10 Pathogenesis of Asthma Genetics Immune regulation Lung factors Age Environment Allergens Infections Microbes Pollution Asthma (Many Phenotypes) What about other approaches to identify asthma phenotypes?

11 Cluster Analysis Perform a multivariate cluster analysis to identify asthma groups who share similar phenotype profiles (defined by the factor scores identified in the variable reduction step) Moore et al. AJRCCM 2010; 181: Population studied in our cluster analysis Severe Asthma Research Program Started in 2000 Determine how severe asthma differs from non-severe asthma

12 Distribution of Variables Composite variables Objective Data 6% 6% 12% 6% 3% 12% 3% % % 6 15% 34 Total Variables, equally weighted Moore et al. AJRCCM 2010; 181: % PFTs: Baseline, Max Demos: Race, Gender, Ages Atopy; Skin tests Meds Triggers: Infxn, ASA, Allergy Sxs: Activity level HCU: Past 12 months Family Hx: Parents, Sibs Smoke Exposure Hormones PMH: GERD, HTN CLUSTER ANALYSIS: 5 CLUSTERS Cluster 1 n=110 Cluster 2 n=321 Cluster 3 n=59 Cluster 4 n=120 Cluster 5 n=116 P-value Age at Enrollment Gender (%female) Race (% Cauc/AAOther) Body Mass Index (BMI) Age of Asthma Onset (yrs) Asthma Duration (yrs) /29/ /30/ /22/ /33/ /20/ < < < < Baseline Lung Function* FEV1 % Predicted FVC % Predicted FEV1/FVC < < < Maximal Lung Function FEV1 % Predicted FVC % Predicted < < Atopy: % with 1 pos skin test 85% 78% 64% 83% 66% *Pre-bronchodilator values (>6 hours withhold of bronchodilators). Post-bronchodilator values after 6-8 puffs of albuterol Moore et al. AJRCCM 2010; 181:

13 CLUSTER ANALYSIS: 5 CLUSTERS Cluster 1 n=110 Cluster 2 n=321 Cluster 3 n=59 Cluster 4 n=120 Cluster 5 n=116 P-value Corticosteroid Use (%) None Low-moderate dose ICS High dose ICS* Oral or Systemic CS** Total Controllers(%) None 2 3 Health Care Utilization Pst Yr None 1 Urgent Visit and/or ED 3 Oral CS burst/yr Hospitalization 45% 38% 10% 11% 41% 41% 19% 67% 20% 11% 7% Moore et al. AJRCCM 2010; 181: % 40% 28% 10% 26% 46% 29% 61% 25% 19% 9% 14% 37% 49% 17% 10% 35% 54% 41% 34% 36% 15% 15% 18% 63% 39% 12% 33% 56% 38% 39% 46% 23% 5% 16% 78% 47% 4% 28% 67% 32% 42% 42% 28% * High dose ICS dose equivalent to 1000 fluticasone propionate daily; **Chronic oral corticosteroids (OCS) 20 mg daily or other systemic steroids in the past 3 months. Controllers include LTRA, ICS, LABA, theophyllines, OCS, omalizumab. P value from Chi-Square Analysis of ranked ordinal composite variables. < < < What about inflammatory markers, like eosinophils

14 Asthma Exacerbations and Sputum Eosinophil Counts: A Randomized Controlled Trial. Green et al. Lancet 2002; 360: Evaluated whether inhaled corticosteroid treatment directed towards reducing the sputum eosinophils was more effective than standard guideline care. Green et al. Lancet 2002; 360:

15 Cumulative Asthma Exacerbations in the BTS Management Group and the Sputum Management Group Green et al. Lancet 2002; 360: Haldar et al. Mepolizumab and exacerbations of refractory eosinophilic asthma. N Engl J Med 2009; 360: Evaluate the effect of reducing sputum eosinophils in patients refractory to usual asthma treatment Recruited subjects with persistent airway eosinophils despite aggressive anti-inflammatory treatment

16 Baseline Characteristics of Subjects in the Intention-to-Treat Population Characteristic Mepolizumab (N=29) Placebo (N=32) P Value Age (yr) Mean Severe exacerbations per subject in previous year (no.) FEV 1 after bronchodilator use (% of predicted value) 78.1± ± Eosinophil count in sputum (%) 6.84 ± ± Eosinophil count in blood (x10-9 /liter) 0.32 ± ± Dose of inhaled corticosteroid beclomethasone dipropionate equivalent (µg) Daily dose Use of oral prednisolone Regular use (% of subjects) Haldar, et al. NEJM 2009; 360: Haldar, et al. NEJM 2009; 360:

17 Haldar, et al. NEJM 2009; 360: How can phenotypic features be used to select patients more likely to respond to a specific treatment?

18 MA Berry et al. Evidence of a role of tumor necrosis factor-α in refractory asthma. N Eng J Med 2006; 354: Objective to evaluate the potential role of TNF-α in asthma Identified patients with treatment refractory asthma Selected normal subjects and asthma patients with low and high peripheral blood mononuclear cell expression of TNF- α receptor Berry et al. N Engl J Med 2006; 354:

19 Baseline Characteristics of the Subjects Berry et al. N Engl J Med 2006; 354: Berry et al. N Engl J Med 2006; 354:

20 Phenotypic characteristics based upon gene activation profiles PG Woodruff et al. T-helper type 2-driven inflammation defines major subphenotypes of asthma. Am J Respir Crit Care Med 2009; 180: To determine whether clinical heterogeneity is reflected in the heterogeneity of molecular mechanisms related to Th2 inflammation Using molecular approaches (microarrays and PCR), IL-13 inducible genes from bronchial brushings were determined

21 Gene expression microarray Heatmap depicting unsupervised hierarchical clustering of POSTN (periostin), ClCA1 (chloride channel regulator), and SERPINB2 (serpin peptidase inhibitor, clade) following IL-13 activation of epithelial cells. Woodruff et al. Am J Respir Crit Care Med 2009; 180: Relative expression of three genes induced by IL-13 Woodruff et al. Am J Respir Crit Care Med 2009; 180:

22 Expression levels of the Th2 cytokines, IL-4, IL-5, IL-13, in bronchial biopsy homogenates Th2 high asthma Th2 low asthma Normals Woodruff et al. Am J Respir Crit Care Med 2009; 180: Do patients with Th2-high asthma respond differently to inhaled corticosteroids?

23 Responsiveness of Th2-high asthma to inhaled steroids Woodruff et al. Am J Respir Crit Care Med 2009; 180: Subject characteristics and bronchoscopic features by a Th2-asthma phenotype Health Control Subjects Subjects with Asthma Th2 Signature Low Th2 Signature High P value Sample size Age, years FEV 1 % predicted Methacholine PC <0.001 IgE, IU/ml BAL eosinophil % FEV 1 with fluticasone at 4 wk, L N/A 0.03 ± ± FEV 1 with fluticasone at 8 wk, L N/A 0.04 ± ± Woodruff et al. Am J Respir Crit Care Med 2009; 180:

24 What is the future for treatment of asthma based upon individual patient characteristics? Determine associations between phenotype characteristics and genotype Develop patient profiles to detect Disease course At risk factors (exacerbations, loss of lung function) Treatment selection This approach promises to have greater specificity, predictability, effectiveness, and efficiency